Closer sagittal and meridional chart lines indicate more 'natural' out of focus areas.

Remember that MTF charts are good for comparing similar lenses, so comparing ones from the 14mm f2.8L and 300mm 2.8L won't tell you much at all, whilst comparing the EF14 2.8L with the EF14 2.8L II will show meaningful differences. Note that other manufacturers may have different ways of displaying such information that may or may not match up with the Canon figures.

The newly designed lens incorporates aspherical and UD elements to achieve the very highest standards of image fidelity. With the latest Ultrasonic Motor for fast and accurate auto focus and the addition of dust and moisture sealing, it replaces the enormously popular EF14mm f/2.8L USM.

The EF 14mm f/2.8L II USM features:

Extreme resolving power, superb contrast and sharpness across the frame through the use of aspheric and UD lens elements
Large f/2.8 aperture for low-light shooting
Latest Ring-type Ultrasonic Motor (USM) for fast and near silent auto focus with excellent holding torque
Full-time manual focus override via a large rubber ring that does not rotate during auto focus

Super Spectra coatings and optimised lens element shaping to suppress flare and ghosting
Large circular aperture diaphragm for good background bokeh and ‘removal’ of distracting backgrounds at wide apertures
Lens hood and pouch included in the box
L-series construction

The L-series is Canon’s flagship professional lens range, designed and built to meet the needs of the most demanding professional photographers. The optics of the EF 14mm f/2.8L II USM and other L-series lenses represent the pinnacle of optical performance, enabling focal length/speed/quality combinations not readily attainable using traditional optical technologies.

New perspectives

The lens’ ultra-wide 114° angle of view can be used by photographers to dramatic effect. Effective for photographing buildings and other large subjects where the photographer cannot get enough distance to include everything in the frame, the EF 14mm f/2.8L II USM is also ideal for small interiors. The lens’ closest focusing distance of just 20cm allows photographers to get remarkably close to subjects for creative wide-angle shots.

Aspherical and UD elements

The EF 14mm f/2.8L II USM incorporates two aspherical lens elements to ensure high corner-to-corner sharpness throughout the focus range and at wide apertures. Pristine image quality is further assured through the incorporation of an Ultra-low Dispersion (UD) element, used to suppress chromatic aberration and associated colour fringing.

Super Spectra coatings

In addition to optimised lens shaping to reduce reflections and the use of anti-reflective material inside the lens barrel, the EF 14mm f/2.8L II USM employs Canon’s patented Super Spectra lens element coatings. These suppress flare and ghosting – more prone to occur with digital cameras due to reflection off the image sensor. By increasing light absorption, coatings reduce reflections off lens element surfaces to deliver crisp, undistorted images with natural colour balance.

While its large diameter, high-precision aspherical and UD elements, optimized lens element positioning, and flare and ghost-reducing lens coating ensure that this lens delivers the top optical performance in its professional class, Canon has added other features photographers have been asking for--improved dust and water resistance incorporated around the mount, switch panel and focusing ring, and a round aperture that creates a nice background blur and makes it easier to recognize an out-of-focus scene in less than brightly lit conditions. Furthermore, Canon has created a new lens cap specifically for the EF 14mm f2.8L II USM that is held to the lens by a stopper."